Brief Summary
Sometimes referred to as "Future Castiel", Cas is a version of the angel Castiel in an alternative 2014 timeline, as witnessed by Dean Winchester in 2009. In 2012, Lucifer's minions re-released the Croatoan demon virus - in this post-apocalyptic world, most humans have been reduced to murderous zombies. Cas is at Camp Chitaqua with Dean, Chuck and other survivors. Cas informs Dean that sometime after the Croatoan virus was released, the angels left, and so did most of his angelic powers, so that Cas is now effectively human. He can however detect that Dean from 2009 is different from his own Dean. He is embittered at his situation and has immersed himself in drugs, sex and escapism.

In Detail
In 2008, Castiel is among the angels sent to lay siege on Hell in order to rescue Dean Winchester. He is the one who managed to reach Dean's soul, pulls it out and recreates Dean. He does this supposedly on God's command so Dean would aid on Heaven's mission. Along with other angels Castiel has manifested on Earth during that time to prevent the breaking of the 66 seals keeping Lucifer in his cage. If those seals break, the Devil would be released and the Apocalypse would follow in his wake.

When he learns that the archangel Michael actually intends for Lucifer to be released so he can kill him, Castiel ultimately ends up breaking allegiance with Heaven to side with humanity. However, he and Dean cannot prevent Sam (manipulated by Ruby) to break the last seal and freeing Lucifer. Following this, Castiel starts losing his power since he is cut off from Heaven. He embarks on a search for the long absent God, but ultimately discovers that he is not interested in intervening in current events. Castiel is devastated, but works to support the efforts of Sam and Dean Winchester and Bobby Singer in stopping the battle between Michael and Lucifer.

This is his history in the events of Supernatural Seasons 4 and 5, which can be read up on in greater detail as linked above. However, in the episode 5x04 „The End“ Dean is sent into a possible version of the future that never comes to pass within canon. Since this Castiel stems from that possible future, the events of his history differ from the canon events at some indistinct point during Season 5.

In this canon divergence, Dean Winchester refuses to become the vessel for the archangel Michael. His brother Sam Winchester, however, agrees to become Lucifer's vessel sometime in 2009. The devil takes over his body, an event which leaves Dean bitter and hardened. Only his continued refusal to grant Michael his body prevents the ultimate fight between angels and demons from happening. Cas stays by his side during this time.

In 2012, Lucifer's minions release the Croatoan virus in an attempt to wipe out humanity. The Croatoan virus is a blood-borne virus of demonic origin. There is all but no incubation time and the infected show no signs of intelligence, only a murderous rage that leads them to kill/infect others. They can be compared to zombies, even if they're not actually dead, particularly the ones found in the movie „28 Days Later“. Following the release of the virus and the disastrous effect it has on humanity, coupled with Dean's continued refusal to serve as Michael's vessel, the angels abandon Earth fully. Their leaving also bled out Castiel's angelic power, making him effectively human.

By the year 2014, the world can be labelled post-apocalyptic, and most of humanity is either dead or infected. Infected zones are quarantined and what remains of the military kills the infected (calls Croats) on sight. Towns with virus outbreaks are bombed or overrun. Resources are thinning and the situation grows worse with each passing day. Dean Winchester leads a small group of survivors in an improvised camp who have dedicated themselves to trying to kill Lucifer. For the past few years, he has been searching for the Colt, a weapon that can kill demons, meaning to kill Lucifer with it - and with him Sam.

Cas meanwhile buries himself in drugs and sex. When Dean sends his allies on a suicide mission to distract Lucifer's forces so he himself can sneak into the devil's stronghold and kill Lucifer, Cas is well aware that he is walking to his death, and does so with no hesitation to give Dean this shot - and dies as a result.

Loyalty
Castiel's loyalty has been with Heaven all his life, but once Dean wins that loyalty for himself, it stays with him. Cas is ready to give up everything and support his cause to the bitter end. Despite the bitter hopelessness and „I don't have a care in the world“ attitude overlaying that, despite the sex and drugs and sarcasm, the core of Cas remains here – he is loyal to a fault, especially when it comes to Dean, and will die for him and his cause without hesitation. While in his current canon point no other character has gained that level of strong loyalty in spite of all other circumstances, it's not impossible that in due time he could develop similar loyalties to specific people. By the time 2014 rolls around, he seems to have realized that he bet on the wrong horse (he is well aware that it's the end of the world and there is nothing Dean can do about it anymore), but that doesn't mean he regrets making the gamble. He doesn't like all that Dean turned into (in his interactions with 2009!Dean we see that he very clearly misses the way Dean used to be). He disapproves of many of the things Dean does. But he would never consider not following Dean, walking away from him or revoking the loyalty he has freely given to the man.

Affection for Humanity
After rebelling against Heaven, Cas spends an increasing amount of time with Dean, learning more about humanity through Dean's eyes and why their continued existence is worth dying for. Before the world buckles under the oncoming Apocalypse, he learns about self-sacrifice and loyalty, about free will and the importance of family even when family is not always blood. While in the world of the Apocalypse that affection never develops into the fondness and love of OU!Castiel, Cas still has a certain degree of care left to give for the members of Dean's camp, and helps ensure their survival to the best of his ability. While played a bit for laugh, he is depicted as someone on good enough terms with the members of the camp to gather a few around him, provide them with spirtiual guidance... and orgies, but hey, it's safe and in good fun.

Tactician/Soldier
Before his fall, Cas has existed for eons as a soldier of Heaven. Canon regularly shows him as a shrewd tactician, able to work with what he's got to formulate battle strategies, from using quantum physics to hide himself from celestial pursuers, to improvising weapons and double crossing shady allies. While the more supernatural (heh) options among this are no longer available to Cas in his current canon point, his mind remains sharp... or would be, if he weren't high all the time, at least. There's a certain amount of ruthlessness there, too, which can be beneficial to him and his allies - and detrimental to his opposition.

Resilience/Determination
Cas knows that sometimes, regrettable actions are necessary to achieve the larger goal - not unfamiliar to him, having served as a soldier in Heaven's ranks. And sometimes, you just keep marching on until you die instead of bowing and taking the easy way out – he would rather lose everything in the attempt to do the right thing, than let the wrong thing come to pass just to save himself. Even when he knows his path will lead to certain death, and even if he knows, at heart, that the attempt is futile and deemed to fail. Soldiers march on and push through.

Rebel at Heart
At the tail end of S4, after knowing Dean for a year, Castiel makes his first truly free choice – he chooses to rebel, to stand up for what he believes his right, and gives himself over to the side of humanity and Dean's cause, and consequently, certain death long before the apocalypse is unleashed, dying once as an angel, and being resurrected by unknown forces (assumed and later confirmed to have been god). Despite Dean growing more ruthless with the years, Castiel doesn't seem intimidated by him and calls him out on his crap, pushing back, as it were, usually with a good amount of sarcasm, but never by rallying against him or truly ever attempting to divert his path. While he doesn't follow orders blindly the way he did for Heaven, he does ultimately follow them - it's the privilege Dean's earned, to be able to command him. It doesn't mean Cas won't call him out. He's unlikely to throw himself behind another cause or fight out of a motivation of his own - but if people gain his loyalty, he could be feasibly swayed to stand with them, and offer at the very least a token resistance.

No regrets, few hard feelings
„Might have beens“ are thoughts Cas does not really burden himself with terribly. Cas has accepted that it's the end of the world and that he will die for Dean's cause, and he strives to make the "best" of that time for himself. Once he might have literally beaten sense into Dean to correct his course, but they're past the point of that being possible, and so Cas cuts his losses and goes with what he's got. Yes, he misses Heaven. He is bitter about his situation, about what him and Dean have become (Castiel calling Dean his 'fearless leader' is not without a giant scoop of bitterness and sarcasm and challenge towards Dean himself). But he doesn't focus on might-have-beens and tries to drown out awareness of everything he's lost most of the time, instead focusing on what little bittersweet joys he can derive from his remaining existence instead. This extends to people who have wronged him. While Cas might keep them at arm's length, he's unlikely to hold true, deep grudges when he himself has been hurt/wronged. Hurting his loved ones, though... that is a different story.

Bitterness, Self-Loathing, Nihilism
By 2014's post apocalyptic state, Cas has grown bitter with his own lack of angelic Grace and subsequent uselessness, aka mortality, seeing himself as barely more than Dean's cannon fodder. He has no hope for the future, and simply follows Dean's lead in the desparate, futile attempt to kill the Devil and survive. He shrouds himself in empty smiles, sarcasm and a "don't have a care in the world" attitude, sharp-tongued and not hesitant to lash out because of it. Cas knows that the world is lost, and that any attempts to save it are ultimately futile. He knows his existence, his fight, his choices are ultimately meaningless in the grand scheme of things and the march towards the inevitable end, and has no qualms about expressing this to others.

Unhealthy Coping Mechanisms
He buries himself in drugs and sex, because it's a behaviour he has seen in Dean in the past, only less extreme – numbing pain any way you can and just pushing on. According to him, it's the end of the world and he's a useless human without hope anyway, so why not indulge in decadence and do whatever it takes to feel good before the end. Drugs and sex and "I-don't-even-care" attitude are his armor and his mask, although he would never paint himself such a tragic figure. Drugs are a way of numbing all that, engaging in casual but ultimately meaningless sex is a way to use his body for something good that will numb all his pain for a while. Stripping him of all his means of escapism forces him to deal with raw feeling - and it's very obvious from how hard he bangs his last gong that he wants nothing less than that.

Lack of Self-Care/Worth
Castiel has centuries of battle strategies to draw upon, but has arrived at a mental place where his own well-being doesn't matter greatly to him anymore. He wants to survive long enough to see Dean to whatever end the man chooses, and doesn't much care about what state he'll meet his own end in, knows only that it's coming inevitably. While he might try to pull himself together for others, he certainly won't do it for his own benefit, and won't avoid taking risks for his own well-being either. Still unused to listening to his own body, and occasionally unable to do so (see other unhealthy coping mechanisms), Cas might occasionally end up failing to feed himself properly when hungry, failing to sleep when tired, failing to remember why humans have a fight or flight instinct, pumping his body full of drugs, not taking care of his human body, taking risks, provoking monsters - the list is practically endless. Add to that being loyal to a fault to a broken, bitter version of Dean Winchester, and you have a recipe for disaster.

Blunt Sarcasm
Castiel has always been blunt. The end of the world has added an unhealthy dose of hopelessness and bitterness, covered with sarcasm and lewdness. Cas is not at all unlikely to antagonize others through his words by being blunt, sarcastic or lewd, and just altogether rather rude in general.

Feeling
Without drugs, alcohol and other means to numb himself, Cas would experience a great amount of discomfort to actual pain, overwhelmed by feelings and sensations he prefers to keep at arm's length. He's never learned to be able to handle either. Castiel was an angel for years beyond counting. When he falls from Grace during season 5, he is rather vocal about all the downsides of losing his powers and becoming mortal. He gets drunk to numb himself, and canon later confirms via other angels that they find feeling incredibly overwhelming and difficult. Endverse!Cas has walked quite the similar path. Falling from Grace meant feeling more and more - emotionally as well as physically. So not only does he have to start dealing with the impossible human condition physically, with losing his wings, his family, his mission, a friend (Sam), he also starts feeling grief and affection and confusion and sadness, hunger and cold and pleasure and pain, and just general hurt in ways he never could before.

Fear of Infection
The Croatoan Virus is basically a Zombie virus. People can get infected, and they will not stay themselves for long. Castiel has already lost everything he is and was, and just wants to make it through Dean's purpose so he can be done with this world and this life - getting infected instills fear in him. It's a risk he has to live with, and should he get infected, his untimely death (and possibly previous mutation) are inevitable. It's not the way he wants to go, once again stripped of free will and choice, and forced into mindless existence that eradicates every sense of self he's fought hard to keep and was/is willing to die for.

Uselessness
Castiel has always defined himself through missions and his use of others. The loss of his powers has weighed on him, as being mortal renders him useless compared to the strength he had before. When he breaks bones and can't go on raids, he's a liability. He used to be able to heal, smite, fly, and now he's no better than any other dirty, simple human in camp - worse, possibly, due to his drug problem. Being useless is another fear of Castiel's.

Intellect
His intelligence and vast knowledge from his countless eons as a celestial being remain, despite his best attempts at wracking his brain with drugs and alcohol.

Weapons/Combat
Castiel is very apt at using various types of guns and knives due to the "zombie apocalypse"-esque lifestyle and has a reasonable grasp of hand-to-hand combat - although he does not like getting up close and personal due to his lack of supernatural strength and lack of experience with the body he has at his disposal. His former existence as an angel enables him to properly wield blades, too.

Basic First-Aid
It can be safely assumed based on that lifestyle that he has at least minor experience with dressing/stitching wounds, too, and due to his more private choices in lifestyle, has good knowledge of various kinds of drugs (medical and recreational) and their effects, benefits and drawbacks. Whether he cares, is a different question.

Remnants of Angelic Grace
Castiel is, for all intents an purposes, a "mortal Angelic Being" - meaning that while he is not fully human per se, he might as well be. His powers are nearly non-existent except for something best described as a heightened sixth sense, allowing him to gain the slightest touch more insight than he should have about a person. This is extremely limited, however, and isn't equivalent to anything supernatural. He instantly feels that Dean is not "himself", when meeting past!Dean, for example, but doesn't realize he's from the past right away. This is definitely a minor feat that would likely rarely come into play except for vague sensations of something being 'off' when agreed upon with CR.

Potential addiction
From the recreational use of weed to likely not exactly risk-free mixes of pills looted on supply runs, Castiel doesn't say no to anything that gets him high. Running out won't be pleasant.

Human/Mortal
Having fallen from Grace and been disconnected from Heaven for so long, Castiel's Grace has dwindled away. This renders him effectively human/mortal, meaning his body is just as weak - if not more so - than that of other humans. He suffers injury and sickness like others, and sometimes overestimates what he can still do, meaning he also risks injury more than other humans might. He's still getting used to listening to his body, and figuring out natural human impulses like eating when hungry, sleeping when tired, and other basic self-care. By no means helpless, he can be somewhat neglectful with himself.

Headcanons are canon compliant and framed to have no impact on cast mates in games. Mostly they inform how the character is played rather than becoming constant talking points. If ongoing canon reveals information that contradicts the information listed here, the headcanons will be updated/adjusted accordingly.

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